Jennifer L Dickson1, Jane Alsweiler2, Cameron A Gunn3, Christopher G Pretty3, J Geoffrey Chase3. 1. Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand jennifer.dickson@canterbury.ac.nz. 2. Department of Paediatrics, Child and Youth Health, Auckland, New Zealand Liggins Institute, University of Auckland, Auckland, New Zealand. 3. Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand.
Abstract
BACKGROUND: Model-based glycemic control relies on sufficiency of underlying models to describe underlying patient physiology. In particular, very preterm infant glucose-insulin metabolism can differ significantly from adults, and is relatively unstudied. In this study, C-peptide concentrations are used to develop insulin-secretion models for the purposes of glycemic control in neonatal intensive care. METHODS: Plasma C-peptide, insulin, and blood glucose concentrations (BGC) were retrospectively analyzed from a cohort of 41 hyperglycemic very preterm (median age 27.2 [26.2-28.7] weeks) and very low birth-weight infants (median birth weight 839 [735-1000] g). A 2-compartment model of C-peptide kinetics was used to estimate insulin secretion. Insulin secretion was examined with respect to nutritional intake, exogenous and plasma insulin concentration, and BGC. RESULTS: Insulin secretion was found to be highly variable between patients and over time, and could not be modeled with respect to age, weight, or protein or dextrose intake. In 13 of 54 samples exogenous insulin was being administered, and insulin secretion was lower. However, low data numbers make this result inconclusive. Insulin secretion was found to increase with BG, with a stronger association in female infants than males (R(2) = .51 vs R(2) = .13, and R(2) = .26 for the combined cohort). CONCLUSIONS: A sex-based insulin secretion model was created and incorporated into a model-based glycemic control framework. Nutritional intake did not predict insulin secretion, indicating that insulin secretion is a complex function of a number of metabolic factors.
BACKGROUND: Model-based glycemic control relies on sufficiency of underlying models to describe underlying patient physiology. In particular, very preterm infantglucose-insulin metabolism can differ significantly from adults, and is relatively unstudied. In this study, C-peptide concentrations are used to develop insulin-secretion models for the purposes of glycemic control in neonatal intensive care. METHODS: Plasma C-peptide, insulin, and blood glucose concentrations (BGC) were retrospectively analyzed from a cohort of 41 hyperglycemic very preterm (median age 27.2 [26.2-28.7] weeks) and very low birth-weight infants (median birth weight 839 [735-1000] g). A 2-compartment model of C-peptide kinetics was used to estimate insulin secretion. Insulin secretion was examined with respect to nutritional intake, exogenous and plasma insulin concentration, and BGC. RESULTS:Insulin secretion was found to be highly variable between patients and over time, and could not be modeled with respect to age, weight, or protein or dextrose intake. In 13 of 54 samples exogenous insulin was being administered, and insulin secretion was lower. However, low data numbers make this result inconclusive. Insulin secretion was found to increase with BG, with a stronger association in female infants than males (R(2) = .51 vs R(2) = .13, and R(2) = .26 for the combined cohort). CONCLUSIONS: A sex-based insulin secretion model was created and incorporated into a model-based glycemic control framework. Nutritional intake did not predict insulin secretion, indicating that insulin secretion is a complex function of a number of metabolic factors.
Authors: Alicia Evans; Geoffrey M Shaw; Aaron Le Compte; Chia-Siong Tan; Logan Ward; James Steel; Christopher G Pretty; Leesa Pfeifer; Sophie Penning; Fatanah Suhaimi; Matthew Signal; Thomas Desaive; J Geoffrey Chase Journal: Ann Intensive Care Date: 2011-09-19 Impact factor: 6.925
Authors: Vincent Uyttendaele; J Geoffrey Chase; Jennifer L Knopp; Rebecca Gottlieb; Geoffrey M Shaw; Thomas Desaive Journal: Ann Intensive Care Date: 2021-01-21 Impact factor: 6.925